Device for processing a metal surface

ABSTRACT

The invention relates to a device to be used in processing of a surface of metal object to be processed which surface is essentially continuously in onwards motion. According to the invention a processing agent ( 1 ) is to be directed to the surface ( 5 ) to be processed by nozzles ( 6 ) in at least one position so that at most 70 per cent of the surface ( 5 ) to be processed is under processing in one position of directing processing agent ( 1 ).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a device for processing a metal surface of ametal object which is in motion during the processing.

2. Description of Related Art

The U.S. Pat. No. 5,312,530 describes a surface processing device forrunning material. This device is provided with an inner cavity that isfed with a processing agent under pressure. A jet forming slot is usedto direct a well laminar jet of the processing agent under an acuteangle, 40 to 70 degrees, to the running material. The jet forming slotis rotational symmetric and surrounds the path, along which the materialis passed. Further, an;electric electrode is disposed in the cavity,whereby an additional electrode is disposed, in the passage direction ofthe material, slightly spaced from the jet forming spot, whereby abipolar electrolyte cell is formed. It is practical, that a plurality ofprocessing units, each having an inner cavity and a jet forming slot arearranged one after the other in the passing direction of the material.The cavity is annular and it opens towards the axial bore, through whichthe material to be processed runs, through an annular slot. Theprocessing agent emerges through the slot in annular shape of such asmall width that the jet acts as a knife. The electrodes enhance thecleaning effect further. If the electrode disposed with the cavity isconnected to the minus pole whereas the other electrode surrounding therunning material is connected to the plus pole of the rectifier then thesurface to be processed becomes anodic under the narrow jet of theprocessing agent. Thereby, the resistive layer of solved contaminantsand metal ions surrounding the running material will be dissolved andpermits a higher current to pass through the cell.

When using an annular slot as in the referred U.S. Pat. No. 5,312,530segments of the jets from the opposed directions weaken each other sothat the total effect to agitate the surface of the object is not asstrong as the sum effect of the segments of the jets individually couldbe.

BRIEF SUMMARY OF THE INVENTION

The object of the present invention is to eliminate some of thedrawbacks of the prior art and to achieve a new and more viable devicefor processing a metal surface of a metal object which is in motionduring the processing so that the processing agent is fed by jets to thesurface of the metal object. The essential novel features of theinvention are apparent from the appended claims.

According to the invention the processing agent is directed by jets tothe surface of the metal object being in motion through nozzles whichare positioned to each other so that part of the surface to be processedis under processing in one position of directing processing agent. Inone position of directing processing agent to the surface to beprocessed there is at least one nozzle through which a jet of theprocessing agent is directed to the surface so that at most 70 per centof the surface to be processed is under direct influence of the jets.The jet emerges from a hole of the nozzle having maximum width less than8 times of the width of the surface. In the device of the inventionthere are at least two positions of directing processing agent to thesurface to be processed within a distance to each other so thatessentially the whole surface to be processed is at least once under thejets of the processing agent in that time when the surface of the metalobject is going through the device of the invention.

In the device of the invention there is at least one reservoir which isfilled with processing agent. The processing agent is a medium forcoating, electrolytic cleaning or plating which are most suitabletreatments to be processed by means of the device of the invention. Thereservoir is provided with an inlet in one wall and with an outlet inanother wall opposite to the first wall. The inlet and the outlet areused to direct the metal object to be processed in motion of high speedup to 20 to 40 m/s through the reservoir in case of coating. In platingthe typical speeds are from 5 to 40 m/s.

The metal object to be processed is in the device of the invention inthe interaction between the processing agent and the metal surface. Inorder to minimise the so called diffusion layer on the metal surface,the metal object is treated by a strong agitation or mixing of theprocessing agent in a very close vicinity of the metal surface. Aturbulence which will minimise the diffusion layer, is partly caused bythe metal object itself which is in motion through the reservoir of theprocessing agent. In order to increase turbulence in the vicinity of themetal surface, in the reservoir there are installed in at least twopositions at least one nozzle in each position to direct jets of theprocessing agent against the metal surface.

When using the device of the invention the consecutive positions ofdirecting jets are advantageously so operated that the directions of thejets are different. Therefore, the metal surface is processed in eachposition of directing jets so that advantageously the same part of themetal surface is not processed in two consecutive positions. Theconsecutive positions of directing jets can also be in separatereservoirs.

The jet from one position can be directed so that the direction of thejet is essentially perpendicular to the metal surface. The direction ofthe jet can also be such that the jet forms an acute or obtuse anglewith the moving direction of the metal surface to be processed. Thedirections of the jets even in the consecutive positions can bedifferent; one can have direction in acute angle and the other in anobtuse angle. The directions of the jets formed in the same position canbe different depending on the surface to be processed.

DESCRIPTION OF THE DRAWINGS

The invention is described in more detail with reference to the appendeddrawings, wherein

FIG. 1 is a schematic side-view illustration of the preferred embodimentof the invention,

FIG. 2 is a partial and schematic side-view illustration from thedirection A—A of the embodiment in FIG. 1.

In accordance with FIGS. 1 and 2 coating medium 1 is in a reservoir 2.The reservoir 2 is provided with an inlet 3 in one wall of the reservoir2 and with an outlet 4 in the other wall of the reservoir 2 opposite tothe first wall of the reservoir. The metal wire 5 is in onwards motionfrom the inlet 3 to the outlet 4. In vicinity of the metal wire 5 in thereservoir 2 there are installed nozzles 6 for directing jets of thecoating medium to the surface of the metal wire. The nozzles 6 directthe jets of the coating medium to the metal wire surface from differentdirections as shown in arrows. In one position of the nozzles 6 onlypart of the metal wire surface is a target for jets of the coatingmedium.

What is claimed is:
 1. Device used in processing of a surface of a metalobject which surface is essentially continuously in onwards motion,comprising at least one reservoir filled with a processing agent capableof receiving a feed of the metal object, the reservoir provided withnozzles in at least one position, the nozzles installed and positionedwithin the reservoir with respect to each other so that jets of theprocessing agent are directed onto the whole surface of the metal objectprocessed by means of the nozzles, there being at least three nozzlesthat are positioned circumferentially around the longitudinal axis ofthe metal object, in order that at most 70 percent the surface of themetal object processed is under processing in one position of thedirecting processing agent, and so that essentially the whole surface tobe processed is at least once under the jets of the processing agentwhen the whole surface of the metal object is going through the device,a hole of each nozzle from which the jet of processing agent emergeshaving a maximum width less than eight times the width of the surface ofthe metal object.
 2. Device according to the claim 1, wherein at leastone nozzle is installed in one position of directing processing agent.3. Device according to the claim 1 wherein at least two nozzles areinstalled in the same position of directing processing agent in order todirect the processing agent from different directions to the surface tobe processed.
 4. Device according to the claims 1 or 2, wherein at leastone nozzle is installed in respect of the motion of the surfaceprocessed in consecutive positions of directing processing agent inorder to direct the processing agent from different directions to thesurface processed.
 5. Device according to any of the claims 1-3, whereinthe nozzle to used for directing processing agent is installed inessentially perpendicular fashion to the surface to be processed. 6.Device according to any of the claims 1-3, wherein the nozzle to usedfor directing processing agent is installed in an acute angle to thesurface to be processed.
 7. Device according to any of the claims 1-3,wherein the nozzle used for directing processing agent is installed inan obtuse angle to the surface to be processed.
 8. Device according toany of the claims 1-3, wherein the nozzle is a jet nozzle.
 9. Deviceaccording to any of the claims 1-3, wherein the positions of directingprocessing agent are in separate reservoirs filled by processing agent.10. Device according to any of the claims 1-3, wherein the processingagent used is a coating medium.
 11. Device according to any of theclaims 1-3, wherein the processing agent used is a plating medium. 12.Device according to any of the claims 1-3, wherein the processing agentused is a medium for electrolytic cleaning.
 13. The device according toclaim 1, wherein the nozzles positioned circumferentially around themetal object are approximately equally spaced relative to each other andto the longitudinal axis of the metal object.
 14. The device accordingto claim 1, wherein each of the nozzles of the device is longitudinallyspaced apart along the longitudinal axis of the metal object.
 15. Thedevice according to claim 1 wherein there are three nozzles.